Machinery for polishing plate-glass



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J. B. FORD. MACHINERY FOR POLISHING. PLATE GLASS. No. 496,731.

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MACHINERY FOR POLISHING PLATE GLASS.

No. 496,731. l Patented May 2, 1893.z

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MACHINERY FOR POLISHING'PKLATE GLASS.'v No. 496,731.

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1 UNITED STATES PATENTv OFFICE.

JOHN B. FORD, OF CREIGHTON, PENNSYLVANIA.

MACHINERY FOR POLISHING PLATE-GLASS.

SPECIFICATION forming part of Letters Patent No. 496,731, dated May 2, 1893.

Application filed September l5, 1890. Serial No. 365,052. (No model.)

To a/ZZ whom it may concern:

Be it known that I, JOHNB. FORD, of Creighton, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Machinery for Polishing Plate-Glass; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

My invention relates to improvements in machinery for polishing plate-glass;-aud it consists in certain novel features of construction and combinations of parts as will be hereinafter described and pointed ont in the claims.

In the drawings, Figure l represents, part in side elevation and part in section, a detail View of a single polisher, showing one, of various, forms of construction and means for attaching it to an actuating runner or carrier. Fig. 2 is a view, in side elevation, showing part of an actuating runner or carrier with two of its attached polishers, and the glasscarrying table beneath. Fig. 3 is a view, in side elevation, showing a glass polishing machine complete, having two polisher-carriers, provided with polishers according to my invention. Fig. 4 is a plan view of the machine shown in Fig. 3 and Fig. 5 is a view, in side elevation, of one, among many, modificationsof which my invention is susceptible.

I will rst describe the glass polisher, or polishing plate, as I shall hereinafter designate it for sake of convenience. This polishing-plate consists, as shown in detail in one of its forms of construction in Fig. l of the drawings, of an iron casting A, preferably, though not essentially, of circular shape in plan view. This casting may be made dished, as shown, and filled with plaster C, which is retained in its position by irregular spurs, as shown, or by any suitable means. The under side of the plate A is covered with thick felting, or equivalent material D, which may be held in its place by a retaining-ring B. By means of any eective attaching device, such, for instance, as the bolt-and-nut arrangement indicated at F, a metallic arch or stirrup E is firmly attached to the plate A. In the central upper part of this arch is an opening through which very loosely and freely passes a stem L. Upon this stem, 'and securely fixed thereon is a sleeve or enlargement M, of a size larger than the opening in the arch E just mentioned. The stem L is, at its upper end,

tightly secured to its carrier or spider I;-

and for purposes of strengthening, merely, the spider is enlarged, as indicated at K, where the sleeve L passes into it. The stem L is screw-threaded for, the reception of nuts N, which will serve not only to hold the stem firmly in place, but will also allow of the stem being set originally at the point of its proper adjustment. The lower end of the stem L enters quite loosely and freely into a shallow cup or hole formed in the central upper face of the plate A, as shown in Fig. 1. The lower end of the stem L should not extend to the bottom of this cup or hole, but there should be left a free space S, to allow of the plate A moving sufficiently up and down.

I is a frame or spider which carries the stem L andits plate A, dac.

Gis the glass being polished, and H Ithe table upon which the glass is bedded. This table preferably revolves in a horizontal plane, substantially as shown in Fig..3 of the drawings. In this figure the table H is supported on an upright shaft revolved by any suitable gearing H and driven by a steam engine or other sufficient power. All the parts of my entire apparatus should be made in the strongest and most substantial manner, as, in practice, I make the diameter of the revolving table H of from twenty to twenty-six feet, while each of the polishing plates A With its attached parts weighs about ninety-live pounds.

O is a frame made preferably of wrought iron, and made vto extend over the table H as shown. spiders I for carryinga sufficient number of polishing-plates A.

The lever-arrangement P. P. clearly indi- In this frame are journaled twoVA cated in Fig. S-is employed for raising or sii-ed, the modified construction shown in Fig. 5 may be adopt-ed, wherein the stem L shall be permitted to move through its bearing in the spider I, and shall be weighted at its upper end,'or elsewhere, to insu re its gravity acting to keep it in proper association with its polishing plate A. The lower end of the stem L, loosely and freely enters a cup or depression in the central upper face of the plate A, but has no other attachment to said plate. It will be apparent that, although the t plate A, in this modified construction, will operate while polishing in the same manner and. to the same effect as the device shown in Fig. 1 the spider` I, when lifted, will not raise the polishing plate, but will simply withdraw its stem L, and leave the plate upon the glass, to be removed manually'.

Obviously this form of embodiment of my invention, while it possesses the elementary features and functions does not contain all the advantages and conveniences in Vhandl-ing which are secured in the form shown in Fig. 1.

The operation of a polishing machine constructed according to my invention is as follows: The unpolished glass having first been bedded upon the table H and the polishingplates in position, as shown in Fig. 3,the table is revolved, and, by means of the frictional contact between the glass on this revolving table and the polishing plates, the spiders I are themselves given a revolving movement as indicated by the arrows in Fig. 4. Each individual polishing plate, being entirely free to move in any direction, is also allowed to have its own revolving motions whenever its contact with the moving glass beneath imparts the same. Rouge is used, in the usual well known manner, during the operation of the machine. Now, as the table H and the spiders I revolve, the slightest variations between the relative positions of these elements, that have heretofore affected the operation of the polishers, are instantly and automatically compensated because of the ability of each individual polishing plate A, by its own gravity, to rest in perfect and complete contact with the glass.

For certain reasons I prefer that the spiders I shall have a rotary or revolving motion, whether such motion be imparted, as already described, by means of the frictional contact between the polishing-plates and the revolving table or by other and independent means. A bodily-revolving movement for the polishing plates is preferable to a reciprocatin g movement because it avoids all jerking of the plates; is less noisy; requires less power; allows of lighter and cheaper machinery; is attendant with less wear and tear, and exercises a more uniform and even action upon the plates A, thus assisting in securing theirintended perfection of operation.

Having fully described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In a machine for polishing glass, a polishing-plate in combi-nation with a central stem; the connection between said stem and plate being such as to allow the plate free universal movement, whereby, of its own gravity, it shall automatically adjust itself, in operation, to rest in even and entire contact with the glass being polished independent of the central stem, substantially as shown.

2. In a machine for polishing glass, the combination with a spider or carrier of a number of polishing-plates, each plate adapted to have a free universal movement about its actuating stem independent of the other parts of the machine, whereby of its own gravity, it shall automatically adjust itself, in operation, to rest in even and entire con-tact with the glass being polished, substantially as shown. 0

3. In a machine for polishing glass, the combination with a revolving-spider, or carrier, of a number of polishing plates, each plate adapted to have a free universal movement about its actuating stem, whereby, of its own gravity, it shall, in operation, automatically adj ust itself to rest in even and entire contact with the glass being polished, substantially as shown.v

4. In a machine for polishing glass, the combination with a revolving glass-bearing table, spiders for carrying polishing plates, and a number of polishing plates, said plates adapted to have a free universal movement about their actuating stems independent of the other parts of the machine whereby, of their own gravity, they shall automatically adj ust themselves, in operation, to rest in even and entire contact with the glass being polished, substantially as shown.

5. In a machine for polishing glass, the combination with a revolving glass bearing table, revolving spiders for carrying polishing-plates, and a number of polishing-plates, said plates adapted to have free universal movement about their actuating stemsindependent of the other parts of the machine, whereby, in operation, said plates shall automatically adjust themselves to rest in even and entire contact with the glass being polished, substantially as shown.

6. In a glass-polishing machine, the com-v bination with a frame or spider for carrying polishing-plates, and a number of polishing plates, adapted to be raised from theL glassbearing table by the spider when it is lifted, said polishing plates attached to the spider to have free universal movements independent ofthe other parts of the machine, whereby, in operation, they shall of their own gravity, automatically adjust themselves to rest in even and entire contact with the glass being polished, substantially as shown.

In testimony whereof I sign this specification, in the presence of two witnesses, this 4th day of September, 1890.

JOHN n. FORD.

Witnesses:

OHAS. UHLINGER, E. L. FORD.

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